Improvement in tanning by infiltration



idthtitd time @sind @tithe Letters Patent No. 10] ,661, dated April 5,1870.

IMPROVEMENT 1N TANNING BY INFILTRATION.

The Schedule referred to in these LLettera Patent and making part of thesame To all whom it may concern Be it known that I, LOUIS 'l. ROBERTSON,of the city, county, and Stateof New York, have invented a new andImproved Tanning Apparatus; and I do hereby declare the following to bea full, clear, and exact description thereof, which will enablethoseskilled in the alt to make and use the same, reference being had to theaccompanying drawing forming part 'of this specification, in whichdrawing- Figure 1 represents a longitudinal vertical section ofthis'invention.

Figure 2 is a plan or top view of the same.

Similar letters indicate corresponding parts.

This invention relates to a tanning apparatus, which consistsessentially of a reservoir containing the tanning-liquor and atanning-vat situated at a level below the reservoir, being provided witha series of flexible discharge-pipes, through which the tanning-liquoris let down into the hide-s or skins to be tanned, said hides or skinsbeing made up in the form. of bags. capable of holdingthetanning-liquor.

The tanning-vat is separated in two compartments, and the hides or skinsare taken successively from one compartment, placed ou a platform at theend of the vat, filled with tannin g-liquor, tied .up and thrown intothe other compartment, where they are left until the liquor graduallydischarges through their pores, the liquor being returned to thereservoir by means of the pump- After the hides or skins are freed fromthe liquor, they are again charged with fresh liquor from the reservoirand thrown back into the first compartment of the vat, and thisoperation is repeated several times, until the tanning operation iscompleted. Both the reservoir and the vat are provided with falseperforated bottoms covered with hair-cloth or other straining material,whereby the liquor in its passage, through the appartus is strainedtwice, and all the impurities which-the same may take up while acting onthe hides or skins are retained by the strainers, so that the liquor isnot liable to spoil. The reservoir is provided with a coil through whichcold water or cold air can be passed for the purpose of keeping-theliquor cool and sweet without reducing its strength, and the tanning-Vatis surrounded by a cold-water jacket for the same purpose.

For the purpose of introducing into the hides or skins fresh tanningmaterial, so as to increase the strength of the liquor, a'table isprovided, in the top of which is secured a series of funnels, so that anumber of hides or skins (previously formed into bags) can be suspendedfrom said funnels, and that the requisite amount of fresh tanningmaterial can be introduced into each hide or skin previous to its beingbrought into the-vat, where it is filled with liquor from the reservoir,as previously described.

In the drawingq The letter A designates a reservoir, which is placed ata certain elevation above the tanning-vat B, and provided with a falseperforated bottom, a, covered with hair-cloth or other strainingmaterial capable of retaining the impurities which may become mixed withthe tanning-liquor.

The tanning-vat B is divided by a vertical partition, b, -in twocompartments c d, each of which is provided with a perforated falsebottom, covered with some straining material capable of retaining theimpurities of the tanning-liquor, said falsel bottoms being so arrangedthat they can be removed for the purpose of cleaning.

The spaces below the false bottoms communicate, by means of a pipe, e,with a pump, B, from which extends a pipe, f, to the reservoir A, sothat the liquor which collects in tbe4 spaces below the false bottoms ofthe vat can be pumped back into the reservoir. By these means the liquoris caused to discharge rapidly from the hides or skins, the .hides orskins remain dry, and the same liquor isused over and over again, sothat a great saving in tanning material is eiected.

The hides or skins to be tanned are made up into bagscapable ofretaining the tanning-liquor, and one of these bags after the other, istaken up by the workman and placed on a platform, g, which rests on 'theedges of the vat, and which is intended to be loose, so that it can beconveniently shifted from one end of the vat to the other. lVhileresting on the platform the hideis filled with tanning-liquor by meansof a exible pipe, h, which communicates with the space below the falsebottom of the reservoir, and which is provided with suitable stop-cocks,so that the How f the liquor can be regulated at pleasure. In practicethe reservoir will be provided with two or more such flexible pipes, sothat two or more hides or skins can be lled at the same time, thereservoir being situated at such an elevation that the hides or skinsfill rapidly with liquor while they rest on the platform g, so that theworkman is not compelled to support the entire weight of each hide orskin and of the liquor contained therein while it is being lled.

Each hide or skin, after having thus been filled, is tied up and thrownin the second compartment d of the tanning-vat, and, as the lled hidesor skins accumulate in this compartment, the liquor is gradually forcedout through the pores of the hides or skins, and caused to accumulate inthe space below the perforated false bottom of the compartment d, whenceit is pumped up into the reservoir.

After the hides or skins are completely freed from the liquor, (whichwill be the case in from two to four hours,) the platform gis placed onthe end of the compartment d, the-hides or skins -are again lled withliquor and thrown into the compartment C and left there until the liquorhas discharged through their pores. The same operation of filling thehides or skins is repeated.

In practice the pump C communicates with two or more tannin g-vats, sothat, while the liquor discharges through the hides or skins in one vat,the workmen can go on and iillthe hides or skins in the next vat, andthus no time is lost.'v

The tanning-vat B is surrounded by a jacket, i, through which a currentof cold water. or cold air is passed, so that the tanning liquor is keptcool and sweet without decreasingpits strength, which can not beaccomplished when the liquor is cooled by junks of ice' thrown intoit,and, furthermore, the cost. of the ice can be saved if cold water orcold air is on hand. By these means the liquor, which in summer time isliable to becomesour and useless, is kept sweet and no loss of liquor isincurred, and, further'- more, the danger of spoiling the leather bysour liquor is avoided.

The reservoir A'may'be surrounded by a similar jacket, or the liquor inthe reservoir maybe cooled by means of a coil, j, through which coldwater or cold air is passed.

When the liquor in the reservoir'is weak, a suitable quantity of freshtanning material (such as sumac or bark) may be introduced into eachhide or skin. This operation is facilitated by means of a table, D, inthe top of which is secured a series of funnels, K, so that the hides orskins can be conveniently suspended from their spouts, and that saidhides and skins can be readily filled with the requisite quantity oftanning material. To facilitate the operation of suspending the hidesfrom the funnels, the spouts may be plovided with suitable hooks tosupport said hides or s ms.

After the hides or skins have been thus supplied with fresh tanningmaterial, they are introduced into the vat and filled with liquor, asabove described.

What I claim as new, and desire to secure by Letters Patent, is-

1. The reservoir A, placed at au elevation above the tanning-vat B, andprovided with exible pipes, in combination with a movable platformresting on the tanning-vat, and with a tanning-vat divided in twocompartments, substantially in the manner herein shown and described. l

2. The combination'of the tanning-vat B with its false and perforatedbottom, reservoir A, and pump C, substantially as described.

3. The false perforated bottoms covered with haircloth or otherstraining material in the reservoirA and vat B, iu combination with apump, O, substan,

tially as described. .4 4. The water-jacket fi, surrounding thetanning-vat B or the reservoir A, either or both, substantially as andfor the purpose set forth.

5. The eoilj in the reservoir containing-,thetanning liquor,substantially as and for the purpose' described.

This specication signed by me this 11th. day of March,` 1870.

LOUIS T. ROBERTSON,

Witnesses: r

W. HAUFF, E. F. KAsTENHUBER.'

